Cyclic stretch in lung epithelial cells causes a variety of responses, including increased gene transfer and expression following transfection. This increased gene transfer appears to be at the level of intracellular trafficking, perhaps related to the enhanced transcription factor expression and activation seen in stretched lung cells. We hypothesize that cyclic stretch increases the levels of transcription factors and the binding of these factors to plasmid DNA, thus facilitating increased nuclear import of the DNA. This proposal will evaluate 1) the effect of cyclic stretch on the formation of plasmid-transcription factor complexes in the cytoplasm, 2) whether blocking the activation of transcription factors diminishes gene transfer in stretched lung epithelial cells, and 3) if stretch-activated transcription factors alone are sufficient to confer the same degree of stretch-enhanced gene delivery in unstretched lung epithelial cells. At the completion of these experiments, new insights will be gained into the mechanism of stretch-enhanced gene transfer, a promising technique for gene therapy in the injured lung.